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Full text of "Alaskan glacier studies of the National Geographic Society in the Yakutat Bay, Prince William Sound and lower Copper River regions"

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information about conditions here except in connection with certain gravel deposits near the entrance.
Orca Say and Orca Inlet—Topography. These two inlets border Hawkins Island on the northern and southern sides, Orca Bay, which has also been called Cordova Bay, being tributary to Prince William Sound just south of Port Gravina, while Orca Inlet opens into the Pacific Ocean south of Hawkins and east of Hinchinbrook Island. The two inlets unite east of Salmo Point on the eastern end of Hawkins Island, forming a fiord 6$ miles in length with a width of a little less than l£ miles, at the upper end.
Orca Bay extends westward from Salmo Point for at least 18 miles, increasing greatly in width, so that between Gravina Point and Hawkins Island Cutoff it has a breadth of 7£ miles. Simpson and Sheep Bays are its tributaries on the northern side, and on the southern side are Windy Bay, Cedar Bay, and numerous other small indentations, such as Hawkins Island Cutoff and Canoe Passage, which connect this part of Prince William Sound with Orca Inlet and the Pacific Ocean.
Orca Inlet extends southwestward for about 16 miles, not including the portion east of Salmo Point nor that leading to Hawkins Island Cutoff, increasing in width to 3 miles. Odiak Slough enters Orca Inlet at the town of Cordova. A great contrast between Orca Inlet and Orca Bay is that the southwestern two-thirds of the former is so shallow that it is navigable only by small boats, while the latter is a deep fiord, traversed by ships on their way to Cordova.
The shores of both Orca Inlet and Orca Bay are high and steep, as in the case of the other fiords of western Prince William Sound, though in each case the outer, western portions are much lower than the inner portions. The eastern half of each of these inlets has walls rising to elevations of 2000 to 3000 feet or more.
Size of Glaciers. The largest glaciers at present known to be tributary to any of the fiords of eastern Prince William Sound, excepting Port Valdez, descend from the snowcapped mountains east of the end of Orca Inlet. The greater size of these ice tongues is perhaps due to the fact that t.Tn'a part of the Chugach Mountains is higher than that near the heads of Ports Fidalgo and Gravina, or perhaps to the heavier precipitation upon this portion of the mountains nearest the ocean. The largest of these glaciers, none df which reach tidewater, is Shephard Glacier.
Shephard and Adjacent Glaciers. Shephard Glacier which has not been visited or studied by any geologist, though roughly mapped from a distance by Grant and Higgins,1 (PI. XCHI) comes from snowfields a considerable distance back in the mountains. It flows southwestward from the portion of the Chugach Mountains east of the head of Orca Inlet, and has an unusually irregular shape. The upper part has a width of about 1£ miles, and sends two distributary ice tongues northward about a mile into the valley which continues northeastward from the head of Orca Inlet. Below these distributaries the main glacier continues southwestward, for about 8£ miles, with an average width of f of a mile, the terminus being 2 J miles east of the head of Orca Inlet. From this terminus of Shephard Glacier a stream flows to Eyak Lake, through a valley which parallels Orca Inlet. Another glacial distributary east of the main ice tongue flows southward for about 1 \ miles and gives rise to Ibeck Creek which joins the stream of Scott Glacier which flows into the Pacific Ocean east of the valley of Eyak Lake. Shephard Glacier, therefore, has (a) one small distributary whose glacial stream flows directly into the Pacific Ocean;
i Bull. -448, U. S. Geol. Survey, 1910, Pis. I and II; Ibid., Bull. 379,1909, PL IV, facing p. 88.